Japanese Non-examined Patent Publication No.8-223915 discloses a conventional power converter. This power converter changes AC power which is from an AC source into DC power, and gives the DC power to a load. A boost converter and a back converter are arranged in parallel, and either of them operates according to power-supply voltage. These two converters include a switching element, respectively, and supply a current to the load, improving harmonic distortion, by making each switching element turn on and off at a frequency higher enough than the frequency of the AC power. This power converter includes two or more switching elements and one inductor which is shared by these converters. The switching elements are controlled in different patterns in order to give a plurality of current supplying modes. By repeating these current supplying modes, power is supplied to the load, improving the harmonic distortion. However, because, in one of these modes, the current does not flow through the inductor and the load at the same time, energy is stored in the inductor while the current is not supplied to the load. So, the amount of the current inputted into the inductor becomes large temporarily, compared with the average output current to the load. For this reason, the inductor and the switching elements need to withstand voltage; therefore, it was difficult to miniaturize the circuit.